图解Java经典算法插入排序的原理与实现

public class InsertionSort {
    //  插入排序
    public static void sort(Comparable[] a){
       for (int i = 1;i < a.length;i++){
           for (int j = i;j > 0;j--){
               //比较索引j处的值与索引j-1处的值,如果j-1索引处的值大，则交换数据，反之，则找到了合适的位置，退出循环
               if (greater(a[j - 1],a[j])){
                   swap(a,j - 1,j);
               }else{
                   break;
               }
           }
       }
    }
    //比较 v 是否大于 w
    public static boolean greater(Comparable v,Comparable w){
        return v.compareTo(w) > 0;
    }
    //数组元素交换位置
    private static void swap(Comparable[] a,int i,int j){
        Comparable temp;
        temp = a[i];
        a[i] = a[j];
        a[j] = temp;
    }
}

public class InsertionSortTest {
    public static void main(String[] args) {
        Integer[] arr = {3,44,38,5,47,15,36,26,27};
        InsertionSort.sort(arr);
        System.out.println(Arrays.toString(arr));
    }
}
//排序前：{3,44,38,5,47,15,36,26,27}
//排序后：{3,5,15,26,27,36,38,44,47}